ES2793506T3 - Vapor phase corrosion inhibitor compositions and their use, as well as procedures for their manufacture - Google Patents

Abstract

A combination of corrosion-inhibiting substances capable of evaporation or sublimation, containing at least: (1) a substituted 1,4-benzoquinone, (2) a substituted aromatic or alicyclic carbamate, (3) a polysubstituted phenol and (4 ) a monosubstituted pyrimidine.

Description

DESCRIPTION

Vapor phase corrosion inhibitor compositions and their use, as well as procedures for their manufacture

Background of the invention

The present invention relates to combinations of substances such as vapor phase corrosion inhibitors ( corrosion inhibitors with the ability to vaporize or sublimate, vapor phase corrosion inhibitors ( VpCI ) , volatile corrosion inhibitors ( volatile corrosion inhibitors) VCI) and procedures for its application to protect metals commonly used, such as iron, chromium, nickel, aluminum, copper and their alloys, as well as galvanized steels, against corrosion in humid climates.

For several decades, compounds identified as corrosion inhibitors have been used, which also tend to evaporate or sublimate under normal conditions and, therefore, can reach metallic surfaces that must be protected through the gas phase for temporary protection against corrosion of metal objects in closed spaces, for example, in containers, control cabinets or showcases. This way of protecting metal parts against corrosion during storage and transportation is the clean alternative to temporary protection against corrosion with oils, greases or waxes.

All temporary protection measures against corrosion of metals against the influence of aqueous media saturated with air or films of condensed water have the objective, as is known, to preserve the primary oxide layer ( POL), which always it is present in utilization metals after first contact with the atmosphere, from chemical and mechanical degradation (see, for example: E. Kunze (ed.), Korrosion und Korrosionsschutz, Volume 3, Wiley-VCH, Berlin, New York , 2001, p. 1679-1756). When using corrosion inhibitors that preferably act through the vapor phase, it must be taken into account that the metals commonly used and the POL present on their surfaces have different chemical properties. Therefore, vapor phase corrosion inhibitors must be selected primarily according to the type of metal to be protected (see, for example, US 4,374,174, US 6,464,899, US 6,752,934 B2, US 7,824 .482 B2 and US 8.906.267 B2).

For objects and constructions made from different metals and which may also be present in different processing states (rough, ground, polished, etc.), as a consequence, combinations of different inhibitors are also required. corrosion to ensure temporary reliable corrosion protection for metals and surface states in the same container or in a common container respectively. Since these technically mixed metallic objects and components are now very frequently found according to experience, the discovery of suitable combinations of corrosion inhibitors substances acting through the vapor phase is of increasing importance.

The use of such combinations of volatile corrosion inhibitors (VpCI / VCI) in practice should be possible, in particular, according to already established applications, but in a way adapted to the different sensitivity of metals and the surface states that It is necessary to protect in air of different relative humidity and composition, as well as with respect to the compatibility of the individual components with each other.

To achieve reliable protection against corrosion by means of VpCl / VCl for metallic components arranged inside containers and packages whose walls are permeable to air containing water vapor (paper, plastic foil, etc.), it must generally be guaranteed that the active substances are released quickly enough from the corresponding deposit by evaporation and / or sublimation, reach the metal surfaces to be protected by diffusion and convection inside the closed container and form an adsorption film on them before the water is present in humid air it can condense in the same location.

The period of time called the development phase (conditioning or incubation time), during which the conditions for protection against VCI corrosion are established after closing the container / container must not, by its nature, be too long for surfaces metals that are susceptible to corrosion to a higher than average degree, as otherwise the corrosion process will start before the VCI molecules have reached the vicinity of the metal surface.

Depending on the type of metals to be protected and the surface states present, not only must a suitable combination of VpCI / VCI components be used, but these must also be applied in such a way that the so-called phase of development required to develop its effect is adapted to the requirements in question.

Solids that tend to sublimate under normal conditions are known to adjust their evaporation equilibrium with the gas phase more easily the larger their specific surface area. Therefore, provide Such corrosion inhibitors in powder form with the smallest possible particle size can be considered a basic requirement.

finely dispersed powder form, packed in bags made from a material that is permeable to active substances in vapor form (e.g. a paper bag, a porous polymeric foil, a perforated capsule), therefore, it is have been commercially available for a long time. Exposing them inside a closed container together with the metal parts to be protected is the simplest form of practical application of VpCI / VCI (see, for example: E. Vuorinen, E. Kalman, W. Focke, Introduction to vapor phase corrosion inhibitors in metal packaging, Surface Engng. 29 (2004), p. 281 and US 4,973,448, US 5,393,457, US 6,752,934 B2, US 8,906,267 B2, US 9,435,037 and EP 1219727 A2 ). The development phases that can be achieved in this way can also be regulated by the permeability of the walls of such deposits. If mixtures of different substances are to be used instead of individual corrosion inhibitors, it must additionally be ensured that they do not react chemically with each other or lead to the formation of agglomerates, as this would prevent both their emission from the deposit and their required chemisorption in metal surfaces to be protected, or at least these would be more damaged.

Currently, VpCI / VCI are already routinely integrated into modern packaging materials for temporary protection against corrosion, so that their technical application can be carried out easily and also automatically. In this respect, papers, cardboard, foamed materials or non-woven fabrics with a coating containing VCI are as common as polymeric support materials in which the VCI active substances in question have been incorporated in such a way that their issuance from them continues to be possible. Thus, for example, in patents US 3,836,077, US 3,967,926, US 4,124,549, US 4,290,912, US 5,209,869, US 5,332,525, US 5,393,457, US 6,752,934 B2, US 7,824,482, US 8,906,267 B2, JP 4,124,549, EP 0,639,657 and EP 1,219,727 have been proposed various variants, always with the aim of incorporating the VpCI / VCI in a deposit, such as in capsules, coatings or gas-permeable plastic sheets, so as to obtain, respectively, a product from which the VCI components can be continuously evaporated or sublimated. However, achieving this with combinations of various substances and, in this regard, physically establishing approximately the same behavior for each component with respect to migration into the reservoir and emission from the reservoir is, by its nature, complicated, and obviously explains that in many applications with hitherto known substance combinations, in particular for mixed metallic objects and components, optimum VCI corrosion protection properties are rarely achieved. Thus, in particular cases, the different particle sizes of the components of a combination of substances can cause a defective corrosion protection if, for example, the pores related to the structure of the walls of the active substance reservoir are not sufficiently large enough to guarantee the same permeation and sublimation conditions for individual molecules or molecular partners for all components of the active substance mixture.

Experience has shown that the incorporation of VpCI / VCI into a coating agent makes it currently relatively easy to produce coatings on flat packaging materials (paper, cardboard, foamed material, non-woven fabric, etc.) from which they are released. the respective VpCI / VCI with emission rates that guarantee comparatively short development phases for the protection against VCI corrosion. In the first instance, this requires the choice of a suitable coating agent that accommodates the combination of substances incorporated in powder form in a finely dispersed form and with a sufficiently high degree of filler and cross-links on the respective substrate giving a well adhered porous layer. , from which the VpCI / VCI in question can be sublimated with little resistance. With the amount of VpCI / VCI coating agent applied it is also possible to adapt the VpCI / VCI reservoir to the requirements of the shortest possible development phases.

Therefore, the production of packaging materials containing VpCI / VCI has long been carried out by dispersing the active substances in a suitable coating agent and applying the same on a flat support material. Processes of this type with various active substances and coating agents are described, for example, in JP 61,227,188, JP 62,063,686, JP 63,028,888, JP 63,183,182, JP 63,210,285, US 5,958. 115, US 8,906,267 B2 and US 9,518,328 B1.

The incorporation of VpCI / VCI in polymeric support materials, preferably in polyolefins (PO), such as polyethylene (PE) and polypropylene (PP), and the provision of sheets and other PO products (granules, trays, etc.) that emit VpCI / VCI, as proposed, for example, in US 4,124,549, US 4,290,912, US 5,139,700, US 6,464,899 B1, US 6,752,934 B2, US 6,787,065 B1, US 7,824,482, EP 1218567 A1 and EP 1641 960 B1, is currently carried out according to the experience gained to a particularly high extent, if only because these products can be advantageously used for the automation of packaging processes.

However, these polymer-based VpCI / VCI products generally have the disadvantage that the VpCI / VCIs incorporated in the extrusion process through the polymer melt are relatively fixedly encased in the polymer matrix, unlike the deposits of VpCI / VCI described above in powder form or in coatings, and their emission therefrom is only possible in a relatively complicated way. In VpCI / VCI sheets, which are currently commonly used with thicknesses of layer d in the range of 60 µm <d <150 µm, concentrations of active substances that are not as high as, for example, in VpCI / VCI coatings can be incorporated. Furthermore, during the extrusion of masterbatches and sheets in question, losses of VpCI / VCI components usually occur which are difficult to control due to the thermal load that, in this respect, originates. Experience has therefore shown that none of the VpCI / VCI material combinations known to date can provide foils that are suitable for the VCI corrosion protection of metal surfaces prone to corrosion to a degree greater than the average, since due to the above reasons the required relatively short development phases cannot be established. Therefore, the VpCI / VCI sheets that are currently commercially available are mainly used as mass-produced articles that are technologically easy to apply, but are not capable of meeting the highest requirements regarding their corrosion protection properties. VCI.

In order to improve this situation and to outline the packaging with polymeric foils with respect to the introduced VpCI / VCI system, several proposals have been made known. In this regard, it seems obvious that all the measures that allow the emission of the VpCl / VCl components integrated in polymeric sheets only in one direction, oriented towards the metallic part to be protected in the container and equip the opposite side as a barrier. for the same.

For this, it is proposed in documents US 5,393,457 A1, US 7,763,213 B2 and US 8,881,904 B2 to cover with an additional barrier layer foil the package produced mainly with a foil containing VpCI / VCI around the metal part. to be protected. In document US 5,137,700, on the other hand, it is envisaged to laminate the outer face of the VpCI / VCI sheet with a metal or plastic layer that acts as a barrier before its use as a packaging material and to preset the sheet equipped with the VpCI / VCI components as the inner side when the metal part to be protected is packaged. The proposal according to US 8,881,904 B2 to manufacture the multilayer VpCI / VCI sheet from the beginning by coextrusion and in this respect not to dose any VpCI / VCI master mix into the layer located on the outer side, according to our Own experience does not lead to this outer layer of the foil subsequently acting as a barrier against the permeation of the VpCI / VCI components in vapor form. On the other hand, the emission of the VpCI / VCI components from the inner layer to the gas space of the container generally worsens, due to the reduction of the concentration gradient required for it by the migration of the active substances to the outer layer initially devoid of active substances begins already during storage of the coextrusion film in a roll and has as a consequence a reduction of the VCI effect.

As hitherto it has not been possible to achieve an acceleration of the emission of the VpCI / VCI components in question in the interior of the closed container with the use of an additional barrier layer film or by equipping the outer side of a film containing VpCI / VCI as a diffusion barrier, other measures were proposed in order to shorten the so-called development phase for the VpCI / VCI system respectively integrated in a foil package to obtain better VCI corrosion protection properties. One approach in this direction is, for example, coating the inner side of a polymeric sheet with a gel containing the VpCI / VCI components, attached underneath a gas-permeable inner sheet made from Tyvek® 1059 (DuPont) ( see, US 7,763,213 B2), with which it should also be possible to preset significantly higher ratios of the VpCI / VCI components than can be achieved by direct integration into a polyolefin sheet by extrusion.

Another roughly similar approach is to introduce individual VpCl / VCI components or several VpCl / VCl components into an adhesive suitable for subsequent coating of the inner side of polymeric sheets as required (see, for example, EP 2347897 A1, EP 2730696 A1, EP 2 752 290 A1 and US 2015/0018461 A1). If an adhesive has been selected that is compatible with the introduced VpCI / VCI components and that hardens as a porous layer, higher emission rates of these components are actually achieved compared to films in which the VpCI / VCI components are have integrated during extrusion.

And finally, it has also been proposed to spread a VpCI / VCI system as a finely dispersed powder directly on the foil used as packaging material (see, for example, US 8,603,603), arrange it as a press piece with a high level filler (called premix, see document US 6,787,065 B1) together with the metal parts to be protected, or introduced in the form of small granules into a porous foam material having a flat shape, having been laminated on the other side of the same polyolefin thin film (see, for example, US 5,393,457 and US 9,435,037 B2), which represent other possibilities of providing within a foil package a VpCI / VCI system that sublimates with low resistance in a relatively high proportion.

To date, however, all these proposals are too expensive in terms of materials and costs, so in practice when designing high-performance corrosion protection packaging it is preferred to resort, based on experience, to the variants of application of VpCI / VCI systems considered classics already mentioned at the beginning.

As is well known, these also include VpCI / VCI containing oils, there is an increasing demand for products of this type which are suitable for the protection against VCI corrosion of components consisting of different metals and machining conditions. It is known that an oil of this type containing VpCI / VCI protects against corrosion not only the metallic substrate in question on which it has been applied as a thin film, but also surface regions of the same component or neighboring metallic objects, which due to its geometry (eg holes, narrow notches, folded sheet metal layers) could not be coated with an oil film. For this, as with all the VpCI / VCI reservoirs mentioned above, it is again necessary that the VpCI / VCI components now emitted by the oil as a carrier material within enclosed spaces (e.g. containers, containers, cavities) reach through the vapor phase the surface regions of metallic parts not covered with oil, where they form an adsorption film that protects against corrosion.

In patent documents US 919,778, US 3,398,095, US 3,785,975, US 8,906,267, US 1,224,500 and JP 07145490 A, for example, VpCI / VCI oils are described. Since these VpCI / VCI oils emit volatile corrosion inhibitors and also protect non-oil-coated metal surface regions through the gas phase, they clearly differ from preservative oils whose corrosion protection properties have been improved with the introduction of non-volatile corrosion inhibitors and therefore only act in direct contact. Corrosion protection oils of this type are described, for example, in US 5,681,506, US 7,014,694 B1 and WO 2016/022406 A1.

However, most of the VpCI / VCI oils known to date have only been profiled for VCI corrosion protection of ferrous materials. They usually contain higher proportions of one or more amines, so that a relatively high concentration gradient can be effective for their migration into the oil phase and their emission to the atmosphere. Its development phase required to develop its VCI effect is therefore also correspondingly short. In this regard, the amine reaching the metal surface to be protected through the gas phase ensures an alkaline surface pH value in the condensed water there from humid air in which the POL of common ferrous materials it is stable (see, for example: E. Kunze (ed.) loc. cit). Experience has shown that these amine-based VpCI / VCI oils are not suitable for the protection against VCI corrosion of non-ferrous metals (e.g. Al and Cu-based materials) and galvanized steels, as their POL degrades at these high surface pH values with formation of hydroxo complexes and subsequently corrosion begins to occur.

The use of amines that already have a vapor or sublimation pressure under normal conditions as VCI / VpCI has been in practice for many years and has been described in numerous patents (see, for example, E. Vuorinen, et al. , loc.cit. and US 8,906,267 B2). Currently, in this respect, it is preferably limited to the cyclic amines dicyclohexylamine and cyclohexylamine (see, for example, US 4,275,835, US 5,393,457, US 6,054,512, US 6,464,899 B1, US 9,435,037 and US 9,518,328 B1) and the various primary and tertiary alkanolamines, such as 2-aminoethanol and triethanolamine, or their corresponding substitutes (see, for example, E. Vuorinen, et.al, loc.cit. and US 6,752 .934 B2 and US 8.906.267 B2).

On the contrary, the secondary amines previously recommended for use, such as diethanolamine, morpholine, piperidine, etc. they are hardly used technically after it was learned that they readily nitrosize to give carcinogenic N-nitrosamines in the air even under normal conditions.

Since cyclic amines and amino alcohols are liquid under normal conditions, they must first be transformed to the solid state by salt formation for the applications mentioned above (e.g. for emitters containing powder or for incorporation into support materials. polymeric). The amine carbonates, nitrites, nitrates, molybdates and carboxylates in question, the latter being mainly amine benzoates and caprylates, are currently among the most common VCI / VpCI for the protection against corrosion of ferrous materials (see, for For example, documents EP 0990676 B1, US 4,124,549, US 5,137,700, US 393,457, US 6,464,899 A1, US 8,603,603 B2, US 9,435,037, US 9,518,328 B2 and JP 2016-117920 A) .

In particular, in the case of amine carboxylates, both the amine component and the associated carboxylic acid are volatile and, as a result, both reach the metal surface to be protected through the vapor phase. The pH value of the surface that is established there in the presence of water vapor is generally in a neutral range, whereby the corrosion protection effect with respect to non-ferrous metals is generally advantageously influenced. On the contrary, as already noted, amines alone lead to higher alkaline surface pH values, which lead to the occurrence of corrosion, especially in the case of aluminum-based materials and galvanized steels.

Since amines generally have higher vapor pressures compared to associated carboxylic acids under normal conditions, experience has shown that, especially in sheets in which amine carboxylates such as VCI / VpCI have been incorporated, the amine components are they preferably deplete with the passage of time. This inevitably means that only the remaining carboxylic acids are emitted from sheets of this type that are in use or have been in place for a long time.

However, if only carboxylic acids reach the metallic surfaces to be protected through the vapor phase, small acidic surface pH values are established in the presence of humid air. This prevents the adsorption of the carboxylate species on the POL of the metal surface to be protected and therefore counteracts the inhibition of corrosion (see, for example: NS Nhlapo, thesis "t GA-FTIR study of vapors released by volatile corrosion inhibitor model systems ", Fac. Chem. Engng., Univ. of Pretoria, SA, July 2013). However, in the case of ferrous materials in particular, the formation of visible corrosion products does not initially occur in this respect because, as is well known, their POL is converted into a thin covering layer of iron carboxylate. which is unnoticeable without modern optical procedures. However, since said thin salt-type conversion layers are porous, corrosion with hydrogen evolution and formation of corrosion products eventually occurs with continuous exposure to humid air in the iron-based material present in the pores. visible, as is the case, almost immediately, of aluminum materials and galvanized steels under the action of acidic aqueous media. Experience has shown that VCI / VpCI preparations with amine carboxylates are, at best, suitable for the protection against short-term corrosion of ferrous materials, but are not suitable for the protection of mixed metal components.

The same applies to the use of nitrites that act as passivators. With these salts of nitrous acid, the POL of ferrous materials can be made to reproduce spontaneously if it has been destroyed by partial chemical dissolution or local mechanical removal (abrasion, erosion) (see, for example, E. Vuorinen, et.al, loc.cit. and US 6,752,934 B2). Therefore, they have also been used for quite some time as VCI / VpCI. In particular, the relatively volatile nitrite salt of dicyclohexylammonium (DICHAN) has been used as an IVC for the protection of ferrous materials for more than 70 years (see, for example, Vuorinen et al, loc. Cit). Until recently, this DICHAN has been mentioned in numerous patent documents as a component of VCI / VpCI compositions (for example: US 5,393,457, US 6,054,512, US 6,752,934 B2, US 9,435,037, j P 2016 -117920 A and EP 0990676 B1), but always only for VCI corrosion protection of ferrous materials. All known formulations containing DICHAN, in most cases supplemented with additional components such as anhydrous molybdates, carboxylates, benzotriazole or tolyltriazole (see, for example, US 5,137,700, US 5,393,457 and US 6,054. 512) have to date proven to be unsuitable for the protection of metallic components mixed with aluminum and copper materials, as well as galvanized steels for several reasons.

In an effort to develop VpCI / VCI packaging media that can be used not only for the protection of ferrous materials, but at least also for galvanized steels and aluminum materials, several amine-free VpCI / VCI systems have been proposed in which combines a nitrous acid salt (ammonium or alkali metal nitrite) with other substances capable of sublimation, such as various saturated or unsaturated carboxylic acids or their alkali salts, a polysubstituted phenol and / or an aliphatic ester of a hydroxybenzoic acid (see , for example, US 4,290,912, US 6,464,899 B1, US 6,752,934, US 6,787,065 B1, EP 1641 960 B1 and KR 1020160011874 A).

However, other proposals prefer combinations of substances devoid of amines and nitrites, constituted, for example, by various saturated or unsaturated carboxylic acids or their alkali metal salts in combination with an aliphatic ester of a mono- or dihydroxybenzoic acid, an aromatic amide and, if necessary, supplemented with benzotriazole or tolyltriazole for the protection of Cu materials (see, for example, US 4,124,549, US 4,374,174, US 7,824,482).

With the addition of selected polysublimated phenols capable of sublimation, insoluble in water, but volatile in water vapor (see, for example, US 4,290,912, US 6,752,934, US 7,824,482, EP 1641960 B1), bicyclic terpenes and aliphatic substituted naphthalenes (see, for example, US 6,752,934) it was achieved, in fact, to improve the emission of the VpCI / VCI components contained in the respective substance combination even under normal conditions, especially in air with a higher relative humidity, and bring it to the usual level of amines. However, the resulting VCI corrosion protection for both ferrous and common non-ferrous metals requires comparatively highly charged active substance deposits, since in addition to the VpCI / VCI components in question even higher proportions of the substances that act as vehicles.

With the combination of VpCI / VCI proposed in US document 8,906,267 B2, which is constituted by a C ³ to C ⁵ aminoalkyldiol, a monoalkylurea, a preferably polysubstituted pyrimidine and benzotriazole, it was possible to achieve a good protection against VCI corrosion for objects made of various metals and surface states, without adding substances that act as vehicles.

In particular, when VpCI / VCI combinations are incorporated into mineral or synthetic oils, inorganic and organic salts such as alkali metal nitrites, nitrates and carboxylates are not suitable because they are not sufficiently soluble in them. Such VpCI / VCI oils, therefore, have been formulated mainly in the past by using amines as VCI components (see, for example, US 919,778, US 1,224,500, US 3,398,095, US 3,785. 975 and JP 07145490 A), sometimes supplemented with other volatile additives, such as C ⁶ to C ¹² alkylcarboxylic acids and acid esters unsaturated fats (see US 3,398,095). On the other hand, JP 07145490 A claims preparations with carboxylates of ethanolamine, morpholine, cyclohexylamine and various sulphonates. However, all these recipes have in common that under normal conditions, ie at temperatures <60 ° C, only the amine components are emitted and are effective as VpCI / VCI.

Said VpCI / VCI oils are therefore exclusively suitable for the protection against VCI corrosion of iron-based materials. In the case of zinc and aluminum, as is known, together with condensed water, they generally cause an excessively high alkalization of the surfaces, which results in intense corrosion with the formation of zincates or aluminates, before they are finally formed. basic hydroxides and carbonates, for which the term white rust is commonly used. Copper materials, on the other hand, often corrode under the influence of amines with the formation of Cu-amine complexes.

To counteract this deficiency, the VpCI / VCI combination proposed in US 8,906,267 B2 of a C ³ to C ⁵ aminoalkyldiol, a monoalkylurea, a preferably polysubstituted pyrimidine and benzotriazole can be incorporated into a mineral oil or synthetic oil through a solubilizer in such a way that a VpCI / VCI oil is produced with which a good protection against corrosion v C i can be configured for a wide range of commonly used metals. At the same time, it has been shown that it is disadvantageous that only relatively small proportions of the VpCI / VCI components can be incorporated, since the VCI effect, which is very good in the case of freshly prepared preparations, decreases more and more during long-term applications. . The same could be observed if a VpCI / VCI oil of this type were diluted with a common mineral oil.

To meet the demand for oils equipped with VpCI / VCI to meet the temporary protection against corrosion of ferrous and non-ferrous metals with small cavities due to their design, new types of VpCI / VCI systems are therefore required, whose application in the practice is not associated with the disadvantages described. In this regard, of particular interest are preparations that can be processed to give not only a VpCI / VCI oil, but at least also VpCI / VCI dispensers (mixtures of powdered VpCI / VCI components in bags, capsules, etc. ) and VpCI / VCI coated packaging materials (eg, papers, cardboard, foamed materials).

With combinations of said VpCI / VCI that are fully compatible with each other, VCI corrosion protection packages could be produced that are particularly effective and long lasting for the above applications, for example VpCI oil-treated engine block preservation packages / VCI in closed containers with lids, in which additional bags, capsules, etc. have been placed. VCI emitters, or VCI-coated foamed or paper cuttings to always ensure, also in case of long-term storage, the saturation of the gas space of the vessel in question with the VpCI / VCI components as a prerequisite for maintaining VCI corrosion protection.

The object of the invention is to provide substances and combinations of corrosion inhibitors capable of evaporation or sublimation improved with respect to the usual volatile vapor-acting corrosion inhibitors exhibiting the aforementioned disadvantages, which both as a mixture powder as well as incorporated in coatings and oils in climatic conditions of practical interest inside technical containers and similar closed containers evaporate or sublimate with sufficient speed from the corresponding tank, for example a bag containing the VpCI / VCI components, a coating containing the VpCI / VCI components on a support such as paper, cardboard or foamed material, or an oil containing the VpCI / VCI components, and after their adsorption and / or condensation on the surface of the metal parts found in this space guarantee in the same conditions in which the metals used ion are reliably protected against atmospheric corrosion.

Surprisingly, these objectives could be achieved according to the invention by providing the combination of substances according to claim 1. More specific aspects and preferred embodiments of the invention are the subject of the additional claims.

The combination of substances according to the invention comprises at least the following components:

(1) a substituted 1,4-benzoquinone,

(2) a substituted aromatic or alicyclic carbamate,

(3) a polysubstituted phenol and

(4) a monosubstituted pyrimidine.

The proportions of the various components can vary depending on the specific field of application, and one skilled in the art can easily determine suitable compositions in this field by means of routine tests.

In a preferred embodiment of the invention the combination of corrosion inhibiting substances contains from 1 to 30% by mass of component (1), from 5 to 40% by mass of component (2), from 2 to 20% by mass mass of component (3) and from 0.5 to 10% by mass of component (4), respectively with respect to the total amount of the combination of substances.

In this regard, the substituted 1,4-benzoquinone is preferably selected from the group consisting of alkyl- or alkoxy-substituted 1,4-benzoquinones, in particular tetramethyl-1,4-benzoquinone (duroquinone), trimethyl-1,4 -benzoquinone, 2,6-dimethoxy-1,4-benzoquinone (DMBQ), 2,5-dimethoxy-1,4-benzoquinone, 2-methoxy-6-methyl-1,4-benzoquinone and combinations thereof.

The aromatic or alicyclic substituted carbamate is preferably selected from the group comprising benzyl carbamate, phenyl carbamate, cyclohexyl carbamate, p-tolyl carbamate, and combinations thereof.

The polysubstituted phenol is preferably selected from the group consisting of 5-methyl-2- (1-methylethyl) phenol (thymol), 2,2'-methylene-bis- (4-methyl-6-tert-butylphenol), 2-tert-butyl-4-methylphenol, 2,4.6-tri-tert-butylphenol, 2,6-dimethoxyphenol (syringol) and combinations thereof.

Monosubstituted pyrimidine is preferably selected from the group consisting of 2-aminopyrimidine, 4-aminopyrimidine, 2-methylpyrimidine, 4-methylpyrimidine, 5-methoxypyrimidine, 5-ethoxypyrimidine, 4-phenylpyrimidine, 2-phenoxypyridine, 4- (N, N-dimethylamino) pyrimidine and combinations thereof.

In the combination of corrosion-inhibiting substances according to the invention, the components (1) to (4) can be present, for example, in the form mixed with one another or dispersed in water or else in the pre-mixed form in a solubilizer which is miscible with mineral oils and synthetic oils.

This solubilizer is preferably an arylalkylether alcohol customary for oil preparations, such as, for example, phenoxyethanol (Protectol PE), in which the components are present in dissolved or dispersed form.

In addition to the components (1) to (4) according to the invention and, if appropriate, the solubilizer, the combinations of corrosion-inhibiting substances according to the invention can also contain substances already incorporated as individual or vapor-phase corrosion inhibitors. as a mixture of them.

The composition of the combinations of corrosion inhibiting substances according to the invention is preferably adjusted so that in the temperature range up to 80 ° C at a relative humidity (RH) <98% all the components evaporate or sublimate in a quantity and at a speed sufficient to protect against corrosion in the vapor space.

According to the invention, these combinations of substances are used directly in the form of corresponding mixtures or are incorporated according to processes known per se during the manufacturing process of VpCl / VCI packaging materials and oil preparations, so that these packaging materials or The oils act as a reservoir for VCI and the corrosion protection properties of the substance combinations according to the invention can be developed in a particularly advantageous manner.

In one embodiment, the combinations of corrosion inhibiting substances are used as volatile corrosion inhibitor (VPCI, VCI) in the form of mixtures of fine powder or pressed parts (pellets) manufactured therefrom in packaging, the storage or transportation of metallic materials.

However, combinations of corrosion inhibiting substances can also be incorporated into coating materials or coating solutions, preferably in an aqueous / organic medium, and / or colloidal composites, to be coated with the same support materials such as paper. , cardboard, foamed materials, textile fabrics, non-woven fabrics and similar flat materials during the manufacturing process of packaging materials that emit VCI and subsequently use them in packaging, storage and transport processes.

In another embodiment, the combinations of corrosion inhibiting substances are used to make VCI corrosion protection oil from which vapor phase corrosion inhibitors (VPCI, VCI) are emitted.

Such a VCI corrosion protection oil comprises a mineral oil or a synthetic oil and 0.5 to 5% by mass, more preferably 0.8 to 3% by mass, relative to the oil phase. , of a combination of corrosion inhibiting substances according to the invention, optionally in a solubilizer. The composition is preferably adjusted so that from the VCI oil in the temperature range up to 80 ° C at a relative humidity (RH) <98% all the corrosion inhibiting components are evaporated or sublimated in an amount and at a rate sufficient for protection against corrosion in the vapor space.

The substance combinations according to the invention are used above all to protect the wide range of commonly used metals, in particular iron, chromium, nickel, aluminum, copper and their alloys, as well as galvanized steels, in containers and during storage in similar closed spaces, against atmospheric corrosion.

The combinations of substances according to the invention are devoid of nitrites and amines and, advantageously, consist exclusively of substances which can be processed easily and without risks according to procedures known per se and which are classified as non-toxic and non-dangerous for the environment in the proportions to be used. Therefore, they are particularly suitable for the manufacture of corrosion protection packaging materials, which can be used economically on a large scale and without any significant potential risk.

For the incorporation of the substance combinations according to the invention into VpCI / VCI tanks or into packaging materials and oils acting as such, it is generally advisable to first mix the individual substances together in the water-free state in the most suitable way. intense possible using known procedures.

The combinations of substances according to the invention are preferably formulated within the following mass ratios:

Component (1): 1 to 30%

Component (2): 5 to 40%

Component (3): 2 to 20%

Component (4): 0.5 to 10%

The object of the application is explained in more detail in the following examples. As can also be deduced from them, the type and proportion of the individual components present in the mixture according to the invention and the proportion of the mixture in the respective VpCl / VCI tank depend only on the manufacturing conditions of the product. that emits VpCI / VCI in question and the processing aids required for it, but not of the type of metal to be protected against corrosion.

Example 1:

Using the anhydrous components of the substance combination according to the invention and other anhydrous substances that serve as processing aids, the following preparation VCI (1) was produced:

10.0% by mass Tetramethyl-1,4-benzoquinone (duroquinone) 8.0% by mass Benzyl carbamate

6.0% by mass 5-Methyl-2- (1-methylethyl) phenol (thymol),

6.0% by mass 5-Ethoxypyrimidine

20.0% by mass Silica gel (SO2)

10.0% by mass Sodium benzoate (micronized, dg5 at 10 pm) 8.0% by mass 1-H-Benzotriazole

1.0% by mass 2- (2H-Benzotriazol-2-yl) -p-cresol (Tinuvin P, CIBA) 30.0% by mass Non-polar PE wax (CWF 201, ALROKO) 1.0% by mass Calcium stearate (dg5 á 8 pm)

Respectively, 0.5 g of this carefully homogenized powder mixture was packed in a small pre-made bag of Tyvek® 1057 D (54 g / m2), a vapor-permeable plastic sheet, the opening of which is sealed by welding, and this bag it is then placed on a floor insert provided with holes made of PMMA, which guarantees a distance of approximately 15 mm from the surface of the base of the Weck jar that serves to house the test arrangement (Weck® is a registered trademark) (volume 1 l) 15 mm. Under this insert in the soil, 15 ml of deionized water had previously been metered. A 5 cm deep notched PMMA strip was placed on top of the floor insert next to the filled Tyvek® bag. In each case, 4 carefully cleaned test plates (90 x 50 x d) mm of different types were arranged in a vertical position with an inclination of approximately 15 ° from the horizontal at a distance of 10 mm from each other. For each Weck jar there was 1 test plate made of DC 03 steel, cold rolled, low carbon, material No. 1.0347, d = 0.5 mm, aluminum 99.5, d = 0.625 mm (both from Q-Panel Cleveland), Cu-ETP (MKM Mansfelder Kupfer und Messing GmbH), d = 0.5mm and hot dip galvanized steel DX56D Z140MBO (fine grain zinc coating, 140 g / m2 -70/70 g / m2 - 10 pm, ArcelorMittal), d = 0.8 mm.

The Weck jars with the test sheets, the deionized water and the substance combination according to the invention were hermetically sealed, for which a lid with a sealing ring and three clamping clamps were used in each case. After a waiting time of 16 hours at room temperature, the so-called phase

g

development of the VCI components within the container could be considered complete. The individual Weck jars were then exposed for 16 h in a heating cabinet according to DIN 50011-12 at 40 ° C, and then again for 8 h at room temperature. This cyclic loading (1 cycle = 24 h) was briefly interrupted after every 7 cycles, the Weck jars were opened for approximately 2 minutes to replace again the oxygen in the air that had reacted if necessary and to inspect the condition of the surface of the the plates. Exposure was terminated after a total of 35 cycles and each specimen was visually assessed in detail outside of the Weck jars.

With reference to the VCI substance mixture (1) according to the invention, 0.5 g portions of a commercially available VCI powder were tested in the same way. This VCI reference powder (R1) consisted of

28.8% by mass Dicyclohexylamine benzoate

67.1% by mass Cyclohexylamine benzoate

1.5% by mass 1-H-Benzotriazole

2.6% by mass Silica gel (SO2)

Test result:

The test plates of the 4 different metals that had been used together with the VCI material mixture (1) according to the invention had an unchanged appearance after 35 cycles in the 4 parallel test preparations.

In test preparations with the commercially available R1 reference system, only the DC 03 plates were still corrosion free after 35 cycles. The Al 99.5 plates were coated on both sides with a layer of yellowish brown tarnish and individual white pinpoint precipitates, the Cu-ETP plates respectively had dark spots starting from the top extending down to form a layer of black tarnish. In most of the test preparations, the test plates made from galvanized steel were characterized already after 7 cycles by initial patch-like white rust crusts in the edge regions, which grew superficially during the subsequent test cycles.

Consequently, the commercially available R1 reference system is only suitable for VCI corrosion protection of iron-based materials. The example described very favorably highlights the VCI effect of the combination of VCI substances (1) according to the invention, compared to the previous one, with respect to the metals commonly used.

Example 2

A VCI coating agent (2) of the following composition was manufactured by incorporating water-free components of the substance combination according to the invention and other substances required as processing aids to an aqueous polyacrylate dispersion (PLEXTOL® BV 411, PolymerLatex):

1.0% by mass 2,6-Dimethoxy-1,4-benzoquinone (DMBQ)

1.0% by mass Benzyl carbamate

1.5% by mass Thymol

2.5% by mass 2-Aminopyrimidine

55.0% by mass PLEXTOL BV 411

6.0% by mass Methyl ethyl ketone

16.0% by mass Deionized water

10.0% by mass Sodium benzoate (micronized, d95 <10 pm)

6.0% by mass Polymer thickener (Rheovis VP 1231. BASF) 1.0% by mass Antifoam (AGITAN 260/265, MÜNZING Chem.

and, with it, paper bands (70 g / m2 Kraft paper) with a wet application of 15 g / m2 were coated. Immediately after drying the VCI paper (2) according to the invention manufactured in this way in air, it was subjected tested its corrosion protection effect compared to a commercially available corrosion protection paper that serves as a reference system (R2).

The commercially available reference system (R2) with a grammage of 66 g / m2 contained the following active substances according to a chemical analysis:

6.2% by mass Triethanolamine caprylate

3.4% by mass Monoethanolamine caprinate

1.4% by mass Benzotriazole

6.7% by mass Sodium benzoate

Compared to the inventive substance combination of the VCI preparation (2), the total proportion of active substance components in the reference system (R2) was approximately three times higher.

For the comparative tests, test plates of DC 03 steel, cold rolled, low carbon, material No. 1.0347, d = 0.5 mm, aluminum 99.5, d were used again analogously to Example 1 = 0.625mm (both from Q-Panel Cleveland), Cu-ETP (MKM Mansfelder Kupfer und Messing GmbH), d = 0.5mm and hot dip galvanized steel (fine grain zinc coating, 140 g / m2 - 70/70 g / m2 - 10 pm, ArcelorMittal), d = 0.8 mm. The test ritual again corresponded to that described in example 1. The only difference now was that instead of the VCI powder mix provided in a Tyvek bag, the individual Weck jars were now lined with the VCI paper. This was done respectively with 1 circular cutout with a diameter of 8 cm in the lower part, a 13 x 28 cm envelope and another circular cutout with a diameter of 9 cm for the lid, always with the coated side facing the insert. with the test plates to be protected against corrosion. After loading the 15 ml of deionized water again and placing the notched strip with the 4 plates of the perforated piece inserted in the ground, the Weck jar was closed and climatic loading was carried out as described in the Example 1.

In this regard, a waiting time of 16 h at room temperature was initially specified again as the so-called development phase of the VCI components within the closed container. The individual Weck jars were exposed again for 16 h in a warming cabinet according to DIN 50011 12 at 40 ° C, then for 8 h at room temperature. This cyclic loading (1 cycle = 24 h) was briefly interrupted after every 7 cycles, the Weck jars were opened for approximately 2 minutes to replace again the oxygen in the air that had reacted if necessary and to inspect the condition of the surface of the the plates. The exposure was terminated after a total of 35 cycles and each specimen was visually assessed in detail out of the Weck jars.

Test result:

The various test plates which had been used together with the VCI paper produced on the basis of the substance mixture according to the invention VCI (2) had an unchanged appearance after 35 cycles in the 4 parallel test preparations.

In test preparations with the commercially available R2 reference system, only the DC 03 test plates remained devoid of visible rust products during the 35 cycles, but were characterized by a matte appearance compared to the initial state. Test plates made of Al 99.5 had dark tarnish films on both sides that cannot be cleaned.

After only 7 cycles, initial crusts of white rust were found on the edges of the galvanized steel test sheets, which also increased significantly along the surface as the loading continued. The appearance of test plates made from Cu-ETP was non-uniform after 35 cycles. While the appearance of the plate surfaces was unchanged in 2 test preparations, the plates in question were covered in the remaining test preparations in some areas with a thin black tarnish film that cannot be cleaned. This finding could not be excluded either by repeating the trials.

Therefore, the R2 reference system is only suitable for the VCI corrosion protection of iron-based materials, while for Cu-based materials the active substances emitted by the R2 reference system are adsorbed in a evident at such different specific concentrations that defects in the VCI corrosion protection effect occur. On the contrary, the VCI paper (2) produced on the basis of the combination of materials according to the invention, as the example shows, has developed reliable VCI properties compared to commonly used metals even in extremely humid air conditions with exposure long-term.

Example 3

A VCI corrosion protection oil (3) of the following composition was produced by adding water-free components of the substance combination according to the invention and other substances required as processing aids to a commercially available mineral oil:

0.6% by mass Duroquinone

0.1% by mass Benzyl carbamate

0.2% by mass Thymol

0.2% by mass 4-Phenylpyrimidine

92.7% by mass Mineral oil with normal wax thixotropic agent (BANTLEON® LV 16-050-2 base oil) 6.0% by mass Phenoxyethanol

0.2% by mass Tolyltriazole (TTA, COFERMIN®)

After intense stirring, the VCI oil (3) according to the invention resulted in an optically transparent fluid, characterized by an average kinematic viscosity of 25 ± 3 mm2 / s (20 ° C). With reference to the VCI oil (3) according to the invention, a commercially available VCI oil of approximately the same average kinetic viscosity was tested analogously. This VCl reference R3 oil, also formulated on the basis of a mineral oil, contained the following active substances according to a chemical analysis:

11.3 g / kg Dicyclohexylamine

8.2 g / kg Diethylaminoethanol

15.1 g / kg 3.5.5-Trimethylhexanoic acid

3.6 g / kg Benzoic acid

For comparative tests, test plates of DC 03 steel, cold rolled, low carbon, material No. 1.0347, d = 0.5 mm, aluminum 99.5, d = 0.625 mm (both from Q-Panel Cleveland ), Cu-ETP (MKM Mansfelder Kupfer und Messing GmbH), d = 0.5 mm and hot dip galvanized steel (fine grain zinc coating, 140 g / m2 - 70/70 g / m2 -10 pm, ArcelorMittal), d = 0.8 mm. The rehearsal ritual again corresponded to that described in Example 1.

The main difference now was that the notched slats made from PMMA that serve as frames for the test bodies were equipped with 3 pieces of the same type of test body and the test plate placed in the center was coated, to this In this respect, on both sides with the VCI oil to be tested, while the test sheets arranged laterally in each case, at a distance of about 10 mm, were used without application of oil. Thus, the degree to which the oil film applied to the centrally located test plate is capable of protecting from corrosion both the metal substrate directly covered by it as well as the two test plates not coated with an oil film thanks to the emission of the VCI components through the vapor phase inside the closed Weck jar.

Each Weck jar (volume 1 l) therefore now contained the notched PMMA strip fitted with the 3 test plates in question of the same material on the perforated piece inserted into the floor and the 15 ml dosed deionized water below it. After closing the individual Weck jars, climatic loading was carried out as described in Example 1.

In this regard, a waiting time of 16 h at room temperature was initially specified again as the so-called development phase of the VCI components within the closed container. The individual Weck jars were then exposed again for 16 h in a warming cabinet according to DIN 50011 12 at 40 ° C, then for 8 h at room temperature. This cyclic loading (1 cycle = 24 h) was briefly interrupted after every 7 cycles, the Weck jars were opened for approximately 2 minutes to replace again the oxygen in the air that had reacted if necessary and to inspect the condition of the surface of the the plates. The exposure was terminated after a total of 35 cycles and each specimen was visually assessed in detail out of the Weck jars.

Test result:

The various test plates, one of which was coated with the VCI oil (3) according to the invention together with 2 similar test plates without remotely applied oil in a Weck jar that were exposed to the cyclical humid air climate had in the 3 respective parallel test preparations an unchanged appearance after 35 cycles. The oil v C i (3) according to the invention, consequently, ensured good protection against corrosion both for the metal substrates in question in direct contact and for the test plates to which no oil was applied inside the closed bottle due to to the VCI components emitted through the vapor phase.

In the test preparations with the commercially available R3 reference system, the test plates made of DC 03 low alloy steel also showed no signs of corrosion, both in applied oil and without applied oil state, after 35 cycles. In the case of test plates made of Al 99.5, Cu-ETP and galvanized steel, however, this was only the case when oil had been applied.

After 35 cycles, test plates made of Al 99.5 in an applied oil-free state were fully coated with a brown tarnish film, which was generally more intense at the edges of the plates. On the Cu-ETP test plates without applied oil, dark gray to black spots could be observed already after 7 cycles in the upper edge regions, from which after 35 cycles, in most cases, relatively uniform tarnish films that cannot be cleaned were formed.

The most notable changes in appearance were the changes made to the oil-free test plates made of fine-grain galvanized steel. In this regard, after 7 cycles of exposure to humid air, point crusts of white rust could be observed in the border regions, from which larger spots, light gray to white in color, were formed with continuous exposure. to the humid air load.

Therefore, the R3 reference system can only be used in direct contact with the corrosion protection compared to commonly used metals. Active substances that are emitted in the gaseous phase, on the other hand, are only suitable for protection against VCI corrosion of iron-based materials. The oil v C i (3) according to the invention, on the other hand, guarantees, as the example shows, a pronounced protection of multiple metals, since it develops reliable VCI properties in long-term tests with respect to the metals of usual use, even in extremely humid air conditions.

Claims (15)

1. Combination of corrosion inhibiting substances with the ability to evaporate or sublimate, containing at least: (1) a substituted 1,4-benzoquinone, (2) a substituted aromatic or alicyclic carbamate, (3) a polysubstituted phenol and (4) a monosubstituted pyrimidine. 2. A combination of corrosion inhibiting substances according to claim 1, containing 1 to 30% by mass of component (1), 5 to 40% by mass of component (2), 2 to 20% by mass of component (3) and 0.5 to 10% by mass of component (4), respectively with respect to the total amount of the substance combination. 3. Combination of corrosion inhibiting substances according to claim 1 or 2, wherein the substituted 1,4-benzoquinone is an alkyl- or alkoxy-substituted 1,4-benzoquinone. 4. Combination of corrosion inhibiting substances according to one of the preceding claims, wherein the substituted 1,4-benzoquinone is selected from the group comprising tetramethyl-1,4-benzoquinone (duroquinone), trimethyl-1,4 -benzoquinone, 2,6-dimethoxy-1,4-benzoquinone (DMBQ), 2,5-dimethoxy-1,4-benzoquinone, 2-methoxy-6-methyl-1,4-benzoquinone, as well as combinations thereof . 5. Combination of corrosion inhibiting substances according to one of the preceding claims, in which the substituted aromatic or alicyclic carbamate is selected from the group comprising benzyl carbamate, phenyl carbamate, cyclohexyl carbamate, p-tolyl carbamate , as well as combinations thereof. 6. Combination of corrosion inhibiting substances according to one of the preceding claims, in which the polysubstituted phenol is selected from the group comprising 5-methyl-2- (1-methylethyl) -phenol (thymol), 2,2 '-methylene-bis- (4-methyl-6-tert-butylphenol), 2-tert-butyl-4-methylphenol, 2,4.6-tri-tert-butylphenol, 2. 6-dimethoxyphenol (syringol), as well as combinations thereof. A combination of corrosion inhibiting substances according to one of the preceding claims, in which the monosubstituted pyrimidine is selected from the group comprising 2-aminopyrimidine, 4-aminopyrimidine, 2-methylpyrimidine, 4-methylpyrimidine, 5-methoxypyrimidine, 5-ethoxypyrimidine, 4-phenylpyrimidine, 2-phenoxypyrimidine, 4- (N, N-dimethylamino) pyrimidine, as well as combinations thereof. Corrosion-inhibiting substance combination according to one of the preceding claims, which in addition to the components (1) to (4) according to the invention, additionally contains substances already introduced as vapor-phase corrosion inhibitors, either individually or as a mixture of them. 9. VCI corrosion protection oil, comprising a mineral oil or a synthetic oil and a combination of corrosion-inhibiting substances according to one of claims 1-8, preferably in a proportion between 0.5 and 5 % by mass, more preferably between 0.8 and 3% by mass, optionally in a solubilizer. 10. Process for the manufacture of a combination of corrosion inhibiting substances with the ability to evaporate or sublimate, in which at least (1) a substituted 1,4-benzoquinone, (2) an aromatic or alicyclic substituted carbamate, (3) a polysubstituted phenol and (4) a monosubstituted pyrimidine are mixed with each other. Process according to claim 10, in which from 1 to 30% by mass of component (1), from 5 to 40% by mass of component (2), from 2 to 20% by mass of component (3) and 0.5 to 10% by mass of component (4) are mixed together. Use of a combination of corrosion inhibiting substances according to one of Claims 1 to 8 as volatile corrosion inhibitor (VpCI, VCI) in the form of fine powder mixtures or pressed parts (pellets) manufactured from it during packaging, storage or transportation of metallic materials. Use of a combination of corrosion-inhibiting substances according to one of Claims 1 to 8 for incorporation into coating materials or coating solutions, to coat support materials, such as paper, cardboard, foam materials, textile fabrics and similar flat materials therewith. Use of a combination of corrosion inhibiting substances according to one of Claims 1 to 8 to produce a corrosion protection oil from which vapor phase corrosion inhibitors (VpCI, VCI) are emitted. Use of a combination of corrosion inhibiting substances according to one of Claims 1 to 8 or a VCI corrosion protection oil containing the same for the protection against corrosion of commonly used metals such as iron, chromium , nickel, aluminum, copper and their alloys, as well as galvanized steels, particularly during packaging, storage and transport processes.